Bus construction

ABSTRACT

A method for constructing a bus, wherein a module associated with the front end of the bus is separately constructed and assembled to the shell after interior components of the bus have been installed. The shell of the bus can be fabricated at a first work station. The shell can be made transversely or laterally with respect to the longitudinal access of the bus to one or more work stations. At the subsequent work stations, interior components of the bus can be moved through the open ends of the bus. After the majority of the interior components have been installed with respect to the bus, the module supporting the windshield and bumper can be installed with respect to the shell. The module can also support the dashboard and steering column.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.10/350,466 for a Bus Construction, filed Jan. 24, 2003, which claims thebenefit of U.S. Provisional Application No. 60/352,702 for a BusConstruction, filed Jan. 28, 2002, both of which are hereby incorporatedherein by reference.

FIELD OF THE INVENTION

This invention relates to a method of manufacturing a motor vehicle busand to the bus structure resulting from the invention methodology.

BACKGROUND OF THE INVENTION

Buses are typically manufactured by forming a closed shell structureincluding a roof, a structural floor, sides, front-end, and rear-end,moving the closed shell structure along a path aligned with thelongitudinal axis of the structure, and loading components of the businto the shell structure through the windows, doors, or windshieldopening. The components may include, for example, the seats and thepassenger compartment floor. This method is time consuming and laborintensive since it involves loading individual components into the busindividually and through relatively small apertures in the shellstructure.

SUMMARY OF THE INVENTION

According to the invention, the shell structure is formed with an openfront-end; the shell structure is moved laterally from station tostation in a direction generally normal to the lengthwise axis of theshell structure; the interior components of the bus are loaded into theinterior of the shell structure through the open front-end; a front-endmodule is attached to the front of the shell structure to close thefront-end of the bus shell; the wheel assemblies are installed; and theshell structure is moved on its wheels along its lengthwise axis tovarious stations where the windows, doors, windshield, and exteriorcladding are applied from locations generally outside of the shellstructure.

Other applications of the present invention will become apparent tothose skilled in the art when the following description of the best modecontemplated for practicing the invention is read in conjunction withthe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The description herein makes reference to the accompanying drawingswherein like reference numerals refer to like parts throughout theseveral views, and wherein:

FIG. 1 is a perspective exploded view of a bus shell structure accordingto the invention;

FIG. 2 is a perspective exploded view of an alternate shell structure;

FIG. 3 is a layout view of an assembly plant for forming the busstructure;

FIG. 4 is a perspective view illustrating the loading of the seats intothe shell structure; and

FIG. 5 is a perspective schematic view illustrating the loading of thepassenger floor into the shell structure.

DESCRIPTION OF THE PREFERRED EMBODIMENT

As seen in FIG. 4, the plant 10 for assembling the bus structureincludes assembly stations 1-7 and pre-assembly stations 8-17.

The basic bus shell structure 20 is formed in known manner at station 1utilizing known assembly techniques and known jigs. Specifically, shellstructure 20 includes lattice members 20 a forming the sides of theshell, lattice members 20 b forming the roof of the shell, and latticemembers 20 c forming the structural floor of the shell. Note that thefront and rear ends 20 e and 20 d of the shell structure are open. Thefront-end of the shell structure, rather than being formed initially atstation 1 as a fixed part of the shell structure, is formed as aseparate module structure 22 in the pre-assembly area 15. Followingformation of the shell structure 20 at station 1, minus the front module22, the shell structure is moved in a direction lateral to thelengthwise axis of the shell structure, utilizing suitable dollies, tostation 2 where the passenger floor of the bus is installed in overlyingrelation to the structural floor 20 c.

As best seen in FIG. 4, the passenger floor or over-floor 24 may beprepared in two sections 24 a and 24 b at pre-assembly station 8whereafter both sections are moved from pre-assembly station 8 throughthe open front-end 20 e of the shell structure for installation in theshell structure. Floor structure 24 a will be understood to be installedover the usual kick-up overlying the rear axle of the vehicle and floorsection 24 b will be understood to be installed forwardly of section 24a to cover the primary floor area of the shell structure. Floor sections24 a, 24 b may be secured to the shell structure 20 using suitable gluesfor example. Floor sections 24 a, 24 b may be initially installed in theshell structure in an upperwardly tilted position, as seen in dash linesFIG. 4, whereafter they may be pivoted downwardly to their flatinstalled positions.

Following the floor installation at station 2 the shell structure 20 ismoved laterally on the dollies to assembly station 3 where the engineassembly 26, prepared in pre-assembly station 9, may be installedthrough open rear end 20 d of the shell structure and the seats 28,prepared at pre-assembly station 10, may be installed through the openfront-end 20 e of the shell structure. With reference to FIG. 5, theseats may be installed utilizing a forklift 30 positioned atpre-assembly station 10 and equipped with a boom 32 extending forwardlyfrom the mast of the lift truck and including a plurality of pins 34each hangably supporting a bus seat 28. With this arrangement theforklift may be maneuvered to insert the boom 32 carrying the seats 28into the interior of the shell structure 20 through the open front-end20 e of the shell structure to position the seats proximate theirultimate locations in the bus, whereafter it is a simple matter toremove the seats 28 from the respective pins 34 and install the seats inthe bus, thereby minimizing the amount of movement required to installeach seat and specifically avoiding the awkward problem of moving eachseat into the interior of the bus through a narrow window or side dooropening and thereafter moving the seat lengthwise in the bus to itsproper location. The seats are installed in the bus employing the usualbolting techniques.

Following installation of the engine assembly and the seats, the shellstructure is moved laterally on the dollies to assembly station 4 wherefurther interior and engine components are installed with the enginecomponents being prepared at pre-assembly station 11 and installedthrough the open rear 20 d of the shell structure and the interiorcomponents being prepared at pre-assembly station 12 and installedthrough the open front-end 20 e of the shell structure.

The shell structure is thereafter moved laterally on the dollies toassembly station 5 where further interior components may be installedthrough the open front-end 20 e of the shell structure from pre-assemblystation 13 and a heating and air conditioning unit 36 (HVAC), preparedat pre-assembly station 14, may be installed through the rear 20 d ofthe shell structure in overlying relation to engine assembly 26.

The shell structure is thereafter moved laterally on the dollies toassembly station 6 where the front-end module 22, which has been formedat pre-assembly station 15, is suitably attached to the front-end 20 dof the shell structure utilizing, for example, bolts whereby to closethe open front-end 20 e of the shell structure. Module 22 may includeinstrument panel 38, windshield 40, steering column assembly 42,headlamp assemblies 44, front bumper 46, as well as suitable brake,throttle, and shift controls. Alternatively, as seen in FIG. 2, thefront module may include only the windshield and front fascia and bumperof the bus with the instrument panel, steering column assembly, andvehicle controls being formed as a part of the main body shell structure20. Following attachment of the module 22 at station 6, the shellstructure is suitably elevated, the dollies are removed, and front andrear axle/wheel assemblies 48, 50, prepared at pre-assembly station 16,are slid under and suitably attached to the shell structure so that theshell structure is now supported for rolling movement on its wheels.

The bus is now rolled on its wheels in a direction parallel to thelengthwise axis of the shell structure to assembly station 7 where thebus windows 52, doors 54, 56 and side cladding 58 maybe installed fromthe pre-assembly station 17 wherein the installation takes placeprimarily from labor performed outside the opposite sides of the shellstructure.

From station 7 the bus may be moved longitudinally on its wheels tofurther stations (not shown) where further exterior componentry may besuitably added whereafter the bus may be moved to suitable test andinspection stations.

The described bus structure and manufacturing methodology has severaladvantages as compared to prior art structures and methodologies. Towit:

-   -   the use of a modular front-end that is not attached to the main        body shell structure until a later point in the assembly process        allows all of the major interior components of the bus to be        installed through the open front-end of the bus, rather than        through narrow openings provided by the side doors and side        windows of the shell structure where the front-end is fixedly        secured to the main body shell structure prior to the        installation of the interior components;    -   the late phase attachment of the front-end module allows an        L-shaped assembly process wherein the bus is moved initially        laterally through several stations in a direction normal to the        lengthwise axis of the bus whereafter, following attachment of        the front-end module and installation of the axle/wheel        assemblies, the bus is moved in a direction parallel to the        lengthwise axis of the bus. This L-shaped assembly format allows        the provision of pre-assembly areas in the area defined between        the legs of the L and in the areas along the outer faces of the        legs whereby to provide a compact factory floor package plan        with a substantial savings in floor space;    -   the use of the modular front-end allows the front-end to be        removed in the event of a front-end accident and replaced        immediately with a new replacement front-end so that the bus is        out of service only for the time required to install the new        front-end rather than for the much longer time required to        repair the front-end;    -   the use of pre-assembly areas in parallel relation to the main        assembly line to fabricate all of the primary sub-assemblies of        the vehicle minimizes the number of workers working on the bus        as it moves along the main assembly line, whereby to simplify        the assembly procedures along the main assembly line;    -   the use of multiple pre-assembly areas allows specialists in        each sub-assembly operation to be stationed at the respective        sub-assembly areas, whereby to assure accurate, precise        pre-assembly of the various sub-assembly components; and    -   the ability to install the floor through the open front-end of        the shell structure in two large sections is vastly preferable        to the prior art assembly procedure whereby, because of the        closed front-end, the floor is moved into the interior of the        bus in small sections which are thereafter pieced together and        built up utilizing sanding and bondo operations to form the        final composite floor structure.

While the invention has been described in connection with what ispresently considered to be the most practical and preferred embodiment,it is to be understood that the invention is not to be limited to thedisclosed embodiments but, on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the description, which scope is to be accorded the broadestinterpretation so as to encompass all such modifications and equivalentstructures as is permitted under the law.

1. In a motor vehicle assembly line for assembling a mass transportationmotor vehicle body, the mass transportation motor vehicle bodycomprising: an elongate vehicle body lattice structure for supportingseparately assembled roof, floor, and side body panels, the vehicle bodylattice structure including a plurality of seats, floor panels, andhaving an open longitudinal end; and a separate unitary front-end panelhaving a plurality of pre-installed members for enclosing the openlongitudinal end of the vehicle body lattice structure, thepre-installed members including an outer fascia.
 2. The motor vehiclebody of claim 1, wherein the pre-installed members further include abumper.
 3. The motor vehicle body of claim 1, wherein the pre-installedmembers further include a steering column assembly.
 4. The motor vehiclebody of claim 1, wherein the pre-installed members further include atleast one headlamp assembly.
 5. The motor vehicle body of claim 1,wherein the pre-installed members further include an instrument panel.6. The motor vehicle body of claim 1, wherein the pre-installed membersfurther include a windshield.
 7. The motor vehicle body of claim 1,wherein the pre-installed members further include at least one of amember for actuating a braking mechanism, a member for controlling anengine throttle, and a member for initiating shifting of a transmission.8. A mass transportation motor vehicle body comprising: an elongatevehicle body lattice structure for supporting separately assembled roof,floor, and side body panels, the vehicle body lattice structure havingan open longitudinal end; and a unitary front-end module removablyconnected to the lattice structure for enclosing the open longitudinalend of the lattice structure, the unitary front-end module beingentirely detachable from the body lattice structure as a single unit,the front-end module including a front fascia and windshield.
 9. Themotor vehicle body of claim 8, wherein the front-end module furtherincludes a bumper.
 10. The motor vehicle body of claim 8, wherein thefront-end module further includes a steering column assembly.
 11. Themotor vehicle body of claim 8, wherein the front-end module furtherincludes a headlamp assembly.
 12. The motor vehicle body of claim 8,wherein the front end module further includes an instrument panel. 13.The motor vehicle body of claim 8, wherein the front-end module furtherincludes at least one of a member for actuating a braking mechanism, amember for controlling an engine throttle mechanism, and a member forinitiating shifting of a transmission.
 14. A roof support structure fora mass transportation motor vehicle body, the roof structure comprising:an elongate first side rail having a forward end and an aft end; anelongate second side rail having a forward end and an aft end, thesecond side rail displaced away from and aligned substantially parallelto the fist side rail; a first elongate cross-member having a first endattached to the first side rail and a second end attached to the secondside rail; a second elongate cross-member having a first end attachedthe first side rail and a second end attached to the second side rail,wherein the first end of the first cross-member is attached to the firstside rail forward of the first end of the second cross-member, and thesecond end of the second cross-member is attached to the second siderail forward of the second end of the second cross-member.
 15. The roofsupport structure of claim 14, wherein the first cross-member isattached the second cross-member.
 16. The roof support structure ofclaim 14, wherein the first cross-member includes a first beam and asecond beam, an end of the first beam being positioned adjacent an endof the second beam, each of the first and second beams having an endattached to the second cross-member.
 17. The roof support structure ofclaim 14 further comprising a reinforcing member attached to the firstand second cross-members and detached, the reinforcing member beingdetached from the first and second side rails.
 18. The roof supportstructure of claim 14, wherein each of the first and secondcross-members includes a first beam and a second beam, an end of thefirst beam of the first cross-member being attached to an end of thesecond beam of the second cross-member and an end of the second beam ofthe first cross-member being attached to an end of the first beam of thesecond cross-member.
 19. The roof support structure of claim 18, whereinthe end of the first beam of the first cross-member is attached to theend of the first beam of the second cross-member.
 20. The roof supportstructure of claim 18 further comprising a reinforcing member attachedto the first and second beams of the first cross-member and the firstand second beams of the second cross-member.